1. Field of the Invention
The present invention relates to a camera, and more specifically, relates to a camera that detects eye position and adjusts the photographing range.
2. Description of the Related Art
In general, an optical viewfinder or a liquid crystal viewfinder is used for setting a photographing range in order to determine the composition of a photograph in the case of photographing a subject using an electronic camera, a silver salt camera, a video camera, a camera function provided on a portable telephone, and so forth.
In many cases, an optical viewfinder is provided to allow observation of the image by moving the eye close to the eye side of the viewfinder optical system, and on the other hand, a liquid crystal viewfinder is made to allow observation of an image displayed on a liquid crystal display device several inches in diagonal length, from several tens of centimeters away.
The image that is observed via the above-mentioned optical viewfinder is an image formed via a viewfinder optical system, and the image that is observed via the above-mentioned liquid crystal viewfinder is an image formed via a photographing optical system, and because both images are formed via some type of optical system, the images differ from that which a photographer observes with the naked eye.
In other words, if the camera angle is changed in order to change the composition, or to follow the movement of the subject, the changes in the image in the viewfinder at that time will differ from the change observed in an image when the photographer moves his/her head and so forth to observe with the naked eye. Accordingly, the photographer will experience an awkward sensation. A photographer such as a practiced professional photographer will be accustomed to these types of sensations, and can grasp how to move the camera for the desired composition or how to follow the movements of the subject, but for a novice or a general user, overcoming these awkward sensations can be a problem.
Further, in the case of a liquid crystal finder, because the display contrast of the liquid crystal is insufficient, the contrast in the image is markedly lower than in an image observed with the naked eye or an image observed via an optical finder, and further, because the number of image frames captured within one second may not be sufficient, or because the response time of the liquid crystal may be said to be not short enough, when the camera is moved, the rewriting of the displayed images may be slow or residual images may occur, and the image may seem blurred.
Now, in the case that an artist for example wishes to paint scenery, forming an L-shape with the thumb and forefinger of the right hand, and similarly forming an L-shape with the thumb and forefinger of the left hand, and combining these two L-shapes facing each other, as illustrated in FIG. 18, configures a rectangular frame FF, and this method for determining composition by changing the aspect ratio or size of this rectangle frame FF has been used since ancient times. FIG. 18 is a diagram illustrating a situation wherein the composition is determined by using the finger frame. In the case of performing observations via the rectangle frame FF, the observation is made with the naked eye, and accordingly awkwardness felt as when observing via an above-described viewfinder is not felt.
On the other hand, Japanese Unexamined Patent Application Publication No. 2003-195145 describes a camera comprising a taking lens, a release button, distance measuring means which measure the distance between the camera body and the photographer, and control means that change the photographic parameter value of the camera based on the distance measured by this distance measuring means, and further, describes zoom movement position calculation means being provided which calculate the zoom movement position of the above-mentioned taking lens based on the distance measured by the above-mentioned distance measuring means.
Further, Japanese Unexamined Patent Application Publication No. 2001-281520 describes an optical device comprising a camera unit comprising a lens capable of changing the focal length, detecting means for detecting the condition of the eyeball, and control means for changing the focal length of the above-mentioned camera unit based on the detecting results of this detecting means. Further, an optical device is described which comprises a camera unit comprising a drive mechanism capable of changing the optical axis direction of the lens, detecting means for detecting the state of the eyeball, and control means for changing the optical axis direction of the above-mentioned camera unit based on the detecting results of the above-mentioned detecting means. Specifically, a technique is described wherein a line-of-sight detecting sensor or a crystalline lens detecting sensor is positioned in the vicinity of the eyeball of the user, and in the case that the convergence angle is small, the focal length is set to the telephoto side, and the photographing direction of the camera is set to match the direction of line of sight.
However, according to the description in the above-mentioned Japanese Unexamined Patent Application Publication No. 2003-195145, in order to confirm what range will be the photographing range when the zoom position is changed, the above-described awkwardness cannot be eliminated because of the necessity to observe the liquid crystal viewfinder and so forth. Further, because the zoom position is calculated based only on the distance between the camera body and the photographer, even if the distance between the camera body and the photographer is the same, in the case that the angle is different and so forth, the difference in the relative position cannot be employed suitably.
Further, the technique described in Japanese Unexamined Patent Application Publication No. 2001-281520 requires a high-precision and expensive detecting sensor because of the need for detecting the state of the eyeball as described above. Further, the detecting sensor must be positioned in the vicinity of the eyeball, and in the case of applying this type of technology to a camera, the subject image will have to be observed via an optical or electronic eyepiece viewfinder, but in this case, the awkwardness as described above will occur. Further, detecting the condition of the eyeball becomes difficult if the photographer has closed eyes or is wearing sunglasses, so this cannot be said to widely handle the various uses of the users.